The Pollster Who Predicted Trump Thinks Geert Wilders Could Win Too

One of the only polls to predict Donald Trump’s victory caught even its creator by surprise. Arie Kapteyn, an economist at USC, ran the USC Dornsife/Los Angeles Times Presidential Election Daybreak Poll, which consistently said Trump would become president of the United States, even when most other polls did not. (He did.) It also predicted Trump would win the popular vote. (He didn't.)

So, a wash? A footnote in the troubled history of polling? Perhaps. Except Kapteyn is taking his methodology global, to the elections in the Netherlands on Wednesday. And his poll there shows the party of Geert Wilders—a right-wing populist who has called for an end to Muslim immigration and the closure of all mosques (familiar!)—with a slightly better chance to claim more seats than other parties in parliament than an average of all national polls says. If Kapteyn's right, even a thin margin of seats could mean victory for the populists and momentum for far-right parties in Europe.

A string of high-profile polling blunders—from state polls in the US election to the FARC referendum in Columbia—have underestimated populism around the world. Is Kapteyn about to be right(ish) again? Even he isn't sure.

Before going to USC, Kapteyn—who was born in the Netherlands—founded a research institute there called CentERdata, and built a large panel poll called the LISS Panel to gauge national sentiments. In contrast to survey polls, which attempt to contact a wide sample of new respondents every time, panel polls assemble a stable group of people to return to again and again. It's a classic method, but surveys in the US have had an increasingly difficult time contacting representative samples, in large measure because of increased use of mobile phones. Panel polling offers another way to get a reliably responsive group of people.

Since polls seem to be getting less and less reliable as predictors, pollsters themselves are rethinking all their methodologies. “I think there was effectively a 40 year consensus around what made good polling,” Jon Cohen, chief research officer at Surveymonkey, said. “There is no such general agreement now.”

In the Netherlands, the vote for parliament is directly representational, with dozens of political parties vying for the popular vote. (Parties create coalitions to get a majority in parliament after the election.) So Kapteyn's countrywide panel poll may be even more predictive than national polls for president in the US. “After the election, we may have one more data point to see whether this works or not,” says Kapteyn, who says he's more of an economist and demographer than a professional pollster. His specific methodology is, he says, really more of a scientific experiment.

Kapteyn's LISS Panel had never looked at politics before an election. But after what happened in the US last year, the team at CentERdata and Kapteyn decided to add the questions. Researchers conduct the panel online, like most other polls in the Netherlands, where about 94 percent of households have internet access. (The pollsters give computers to participants who don't have it.) A seventh of the 3,500 people involved in the election study respond for each day of the week.

Unlike most polls, the LISS panel also asks voters to give a percentage likelihood of their voting for a given party. “We give people a chance to fully indicate the parties they consider, and their doubts, and that they are not yet certain,” says Boukje Cuelenaere, head of CentERdata’s survey research department. “We think that is necessary because these days a lot of people are uncertain.”

Kapteyn thinks this is how his US poll picked up on enthusiasm for Trump. “This was an election where we could see relatively many people who hadn’t voted in the past. It was like a reservoir of people who were maybe not engaged,” he says. “I think in many of the traditional voter models, these people are more likely to be missed.”

Of course, pollsters still don't think Kapteyn has found a magic solution to their ongoing problems. Maurice de Hond, who runs the Peil.nl opinion panel, says he thinks that by not forcing voters to decide definitively, the LISS polls won't have predictive power. When it's time to vote, de Hond says, "it’s not possible to divide 100 percent to all the parties."

Also, since the daily poll is based on only a seventh of the panel, de Hond says it's harder to use it to gauge greater shifts in the electorate. Fraying relations between the Netherlands and Turkey led to police violence Sunday during pro-Turkish President Recep Tayyip Erdoğan demonstrations in Rotterdam, for example, and a too-small sample size might miss the impact of that tension on the election.

De Hond says these events could be a "game change," and have already improved the poll numbers of the liberal party—but he adds that the violence and rhetoric surrounding Turkey might also give a boost to Wilders's anti-immigration party. That has not been reflected in the polls as yet.

Even Kapteyn doesn't expect a radical outcome for polling methodology. He says he's paying attention to developments in the Netherlands, but remains skeptical about how well his panel will fare in predicting the election. “I don’t follow the polls too closely,” he says—even results from the one he helped devise.